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Title: Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.

Abstract

The film stress of Ni films deposited at near-ambient temperatures from sulfamate electrolytes was studied. The particulate filtering of the electrolyte, a routine industrial practice, becomes an important deposition parameter at lower bath temperatures. At 28 C, elevated tensile film stress develops at low current densities (<10 mA/cm{sup 2}) if the electrolyte is filtered. Filtering at higher current densities has a negligible effect on film stress. A similar though less pronounced trend is observed at 32 C. Sulfate-based Ni plating baths display similar film stress sensitivity to filtering, suggesting that this is a general effect for Ni electrodeposition. It is shown that filtering does not significantly change the current efficiency or the pH near the surface during deposition. The observed changes in film stress are thus attributed not to adsorbed hydrogen but instead to the effects of filtering on the formation and concentration of polyborate species due to the decreased solubility of boric acid at near-ambient temperatures.

Authors:
;  [1]; ;
  1. (IBM/T.J. Watson Research Center, Yorktown Heights, NY)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
875966
Report Number(s):
SAND2005-6077
TRN: US200604%%278
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; BORIC ACID; DEPOSITION; EFFICIENCY; ELECTROCHEMISTRY; ELECTRODEPOSITION; ELECTROLYTES; HYDROGEN; NICKEL; PARTICULATES; PLATING; SENSITIVITY; SOLUBILITY; Films.; Electrodes-Materials.; Electrolytes-Analysis.; Electrodes-Surfaces.

Citation Formats

Hachman, John T., Kelly, J.J., Talin, Albert Alec, and Goods, Steven Howard. Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.. United States: N. p., 2005. Web. doi:10.2172/875966.
Hachman, John T., Kelly, J.J., Talin, Albert Alec, & Goods, Steven Howard. Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.. United States. doi:10.2172/875966.
Hachman, John T., Kelly, J.J., Talin, Albert Alec, and Goods, Steven Howard. Tue . "Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.". United States. doi:10.2172/875966. https://www.osti.gov/servlets/purl/875966.
@article{osti_875966,
title = {Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.},
author = {Hachman, John T. and Kelly, J.J. and Talin, Albert Alec and Goods, Steven Howard},
abstractNote = {The film stress of Ni films deposited at near-ambient temperatures from sulfamate electrolytes was studied. The particulate filtering of the electrolyte, a routine industrial practice, becomes an important deposition parameter at lower bath temperatures. At 28 C, elevated tensile film stress develops at low current densities (<10 mA/cm{sup 2}) if the electrolyte is filtered. Filtering at higher current densities has a negligible effect on film stress. A similar though less pronounced trend is observed at 32 C. Sulfate-based Ni plating baths display similar film stress sensitivity to filtering, suggesting that this is a general effect for Ni electrodeposition. It is shown that filtering does not significantly change the current efficiency or the pH near the surface during deposition. The observed changes in film stress are thus attributed not to adsorbed hydrogen but instead to the effects of filtering on the formation and concentration of polyborate species due to the decreased solubility of boric acid at near-ambient temperatures.},
doi = {10.2172/875966},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}

Technical Report:

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  • Ni and Ni alloys are being developed as baseline materials for LIGA technology and prototyping at Sandia National Laboratories. A conventional, additive-free sulfamate electrolyte has been chosen for pure Ni electrodeposition due to its simplicity and ability to produce ductile, low-stress films. When depositing certain Ni alloys, saccharin is typically employed as an electrolyte bath additive. While saccharin is well known and effective as a stress reliever, it has a significant impact on the microstructure of the deposit and its annealing behavior. The electrodeposition of pure Ni in the presence of saccharin is studied here to understand its effects inmore » the absence of an alloying element (such as Co or Fe). The grain structure and Vickers hardness of Ni deposited with and without saccharin on a rotating disk electrode were all found to be consistent with previous studies available in the literature. The following observations were made: (1) The fine, columnar morphology obtained without saccharin became an equiaxed, nano-sized grain structure with saccharin (from {approx}1.5 {micro}m to {approx}40 nm nominal grain size, respectively). The grain refinement resulting from saccharin is not accompanied with an increase in film stress, in contrast to the grain refinement associated with certain Ni alloys. (2) A change in the deposit texture from weak (210) to (111) along the film growth direction with the addition of saccharin. (3) An increase in Vickers hardness by a factor of {approx}2 (from {approx}170 to {approx}320) upon the addition of saccharin. (4) A rapid decrease in hardness with annealing from the high, as-deposited values for films deposited with saccharin to a value lower than that of annealed Ni from an additive-free bath. (5) Accelerated grain growth during annealing for films deposited with saccharin; this has not been observed previously in the literature to the authors' best knowledge.« less
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  • Stress corrosion cracking (SCC) of Type 304 stainless steel in 20N caustic solution was investigated in the presence of chromate ions, using the constant strain rate (10/sup 7/-10/sup 5//s) technique. Results confirmed that the chromate ions act as an oxidizing inhibitor and prevent caustic cracking. The threshold concentration of chromate was also confirmed to be 0.005M in 20N caustic solution. This chromate concentration was also effective in a mixed caustic-chloride environment of 20N NaOH + 0.1M NaCl. A fast (10/sup -3/-10/sup -1//s) constrant strain rate technique for predicting the SCC acuity of metals was tested with Type 304 stainless steelmore » in 20N NaOH solution. In order to assess the long-term corrosion kinetics of pure nickel in caustic solution, controlled-potential coulometry experiments were done in 10N NaOH at 110/sup 0/C, using several potentials in both the active and the passive regions for over 1000 minutes each. Periodic analysis showed a nickel concentration always considerably lower than expected from the measured coulometric charge, proving the excellent corrosion resistance of nickel in the caustic environment . In fused sodium hydroxide at 350/sup 0/C under four different blanketing atmospheres, nickel was found to have a good corrosion resistance (less than 5 mpy) under all blanketing atmospheres; however, the rate increased with oxidizing condition. The atmospheres in the order of corrosion rate ranked: Air > (Ar + 5 ppM O/sub 2/) > (90% Ar + 10% H/sub 2/) > H/sub 2/. The specimen exposed to caustic under a hydrogen blanket had a shiny surface, whereas the one under the air blanket was covered with a black film of NiO. 10 fig, 4 tables. (DLC)« less